McGrath will replace Alex Poots, who oversees his final festival this summer before heading to New York to run a new arts space, the Culture Shed.

Six years ago McGrath helped launch the first English-language national theatre for Wales, a wildly ambitious project on a small budget which staged productions all over Wales, from Aeschylus on the army ranges of the Brecon Beacons to a Passion Play in Port Talbot.

Manchester international festival founding director off to New York

He is now looking forward to a new challenge. “The speed and success with which Manchester international festival has established itself in the top tier of festivals worldwide has been astonishing,” he said. “Like many others across the globe, I’ve been deeply impressed by the festival’s unique and brilliantly realised artistic policy, and the unprecedented level of local commitment from government and business.”

The appointment represents something of a homecoming, as McGrath was artistic director of Manchester’s Contact theatre between 1999 and 2008, during which time he helped reinvent it as an industry leader in working with diverse young artists.

He returns to a city that is buzzing artistically. Next week there will be the opening of the new cultural hub, Home, a merger of the Cornerhouse and the Library theatre. McGrath will start work part-time in September, planning for the next festival in 2017.

Guardian and BAC present debate about nationhood at Home in Manchester

Read more

His colleagues in Wales are sorry to see him go. Dai Smith, the chair of Arts Council Wales, said there were many people to thank for the success of National Theatre Wales. But he added: “The name of John McGrath is pre-eminent. John gave everyone the confidence to be both what we are – a Welsh company with local purpose – and to release what we possess within us at our best: a vision and a reach that is truly global.”

• This article was amended on 14 May 2015. An earlier version described National Theatre Wales as “the first national theatre for Wales”; it was beaten to that title by Theatr Genedlaethol Cymru, its Welsh-language counterpart, founded in 2003.